Delayed action electric switch



I April 9, 1935. c. A. TURNER DELAYED ACTION ELECTRIC SWITCH Filed June 6, 1931 Patented Apr. 9, 1935 UNITED STATES PATENT OFFICE Charles A. Turner,

Chicago, IlL, asalgnor, by

mcsne assignments, to Howe Manufacturing Company, W Delaware Del., a corporation of Application June 6, 1931, Serial No. 542,526

3 Claims.

My present invention relates to the provision of a and and desirable to delay the occurrence of one or more operations, and

obj e a necessary sequence or series of my present invention has for its ct the provision of simple, dependable and economical means for delaying the opening or closing of a circuit a definite time after the switch is thr mercury in an air own. am aware that electric switches employing evacuated tube for opening closing circuits is not new, but I believe that my construction, as will mits the securing hereafter be seen, which perof an air evacuated mercury containing switch tube without special evacuating mac hinery secures substantial economies in the construction of such apparatus.

attain the foregoing objects and results by means of the structure illustrated in the accom- D y awing,

in which Fig. 1 is a horizontal central section of a switch emb Fig. 2 is a vertical central not Similar reference parts throughout the The construction of ployment of a length odying my invention.

yet closed.

characters refer to similar respective views.

the switch involves the cmof tubing 5, preferably made of glass so that the operation of the switch may be observed, together with an intermediate plug 6 and two end plugs l and 8. The plugs E3,

1 and the inner end of a smooth friction fit in The plug 8 are made to have the bore of the tube 5. plugs are made from electric insulating material, preferably of bakelite or some other-condensite product which mer is inert in the presence of cury. In the plug 8 are embedded metallic conductors 9 and iii which project upon the inside min ject securing thereto conductors l3 and i i. termediate plug 6 has provided in its of the plug in spaced relation to provide terals or contacts H and i2, and which also proupon the outside of the plug to permit of the opposite ends conical recesses -!5, which preferably extend from its end edges, as a base, to the center or axis of the plug as an apex. A short passageway it connects the apexes of cess ical bore or the rees IS-l The angle of the walls of the conrecesses l5-I5 are preferably such as to The insecure the draining of the mercury from one side of the plug to the other when the switch is put in either on or off position. Embedded in the plug 6 is or are one or more rods ll, preferably of or covered with bakelite, extending in the direction 5 of the plug 1. The inner face of the plug 7 is perforated, as at l8, to receive and provide a close fit for the rod or rods I1. The outer face of the plug I is bored to produce an enlarged bore IS. The bores l8 and I9 communicate and the bore 10 I9 is of such size as to accommodate the rod I! provided with a nut 20. In the plug 1 an additional bore 2|, tapped to receive a sealing screw 22, may be provided.

The method of assembly of the above described parts is as follows: The bore of the tube 5 at the end for the reception of plug 8, is coated with a solution of cellulose acetate, or some other the tube until the same is filled. The plugs 6 and 1 are next inserted and forced down in the tube until all three plugs are in contact and until excess mercury exudes through the bore 2|. Sealing solution is then placed in the bores 19 25 and 2| in the plug 1 and in the bore of the tube 5 outside of the plug 1. The sealing screw 22 is screwed into the bore 2| and the plug 1 is withdrawn to the end of the tube. The withdrawal of plug I to the end of the tube 5, through the operation of the rod. l1, secures the withdrawal of the plug 6 from its contact with the plug 8 and a spacing of plug 6 between plugs i and 8.

Another mode of assembling the apparatus consists in seating and sealing the plug 8 in the end of the tube 5, as hereinbefore described. Place a sufficient amount of mercury in a tube so that when the plug 8 is forced into and sealed in its final position in the center of the tube, the chamber between the plug 8 and the plug 8 will be completely filled with mercury. The other end of the tube is then filled with mercury and the plug :7 is pressed and sealed into its position. The end of the tube containing the plug l is then A capsized in abath of mercury with the end of the tube containing the plug 8 withdrawn from the bath of mercury sufiiciently far to permit the mercury to drain from the portion of the tube beween plugs E and 8, at which time the screw 22 is inserted and sealed in the bore 2i. When the method of assembly last described is employed, the rod or rods it will be unnecessary.

Either of the above described series of operations secures the evacuation of air from the in- 55 terior of the tube ii without any special evacuating or pumping apparatus.

I have illustrated the tube 5 supported in a ring or annulus 2 3 from. which extends a perforated ear 25, through the perforation of which is m aide it operated by a tilting mechanism which may be employed for throwing the switch into on or ofi position. it is obvious, however, that the tube may be equally well supported and tipped in a number of other ways.

When the tube is thrown into off position the mercury drains away from the portion of the bore of the tube between plugs t and B through the passage or bore it into the space between the plugs ii and l until either of the contacts H or i2 is free from the mercury, when the switch is open. When the tube 5 is in on position, as shown in Fig. 3, the mercury drains from the space between plugs 6 and a through the passage it in plug 6 and into the space between the plugs 5 and 8 accumulating in the lowest portion thereof until the terminals H and 52 are submerged, when the circuit is closed. The amount of delay secured in this way may be varied by increasing or decreasing the size of the tube 5 and thecapacity of the bore 86, or by changing the vertical relation of the contacts M and i2 and their spacing or separation. I do not thing it is desirable to have the bore 56 very long, but the other factors may be changed between quite large limits so that the closing or opening of the circuit after the switch-is thrown, may be delayed for a predetermined time from a few seconds up to a minute or more.

Having described my invention what 1 claim as new and desire to secure by Letters Patent is:

l. A delayed action switch comprising a tiltable tube, a partition intermediate the ends of said tube having conical recesses in its opposite faces and a channel connecting the apexes of said recesses, end plugs for said tube, a quantity of mercury enclosed within said tube and said end plugs and spaced conductors extending through and protruding from the faces of one of said end plugs.

2. A delayed action switch comprising a tiltable tube, a partition intermediate the ends of said tube having conical recesses in its opposite faces and a channel connecting the apexes of said recesses, end plugs for said tube, a quantity of mercury enclosed within said tube and said end plugs, spaced conductors extending through and protruding from the faces of one of said end plugs and means co-acting between said intermediate partition and one of said end plugs for securing the spacing of said. elements upon the withdrawal of said end plug to the end of said tube.

3. A delayed action switch comprising a tiltable tube having spaced electric contacts in one end thereof, a quantity of mercury and an intermediate partition within said tube, said partition having conical recesses in opposite faces thereof and a passageway connecting the apexes of said recesses, whereby said mercury will drain from. one side to the other of said partition upon the tilting of said tube.

V CHARLES A. TURNER. 

